1. Field of the Invention
The present invention relates to a light-emitting device.
2. Description of the Related Art
In recent years, self-luminous display devices, light-emitting devices, and the like including light-emitting elements that utilize electroluminescence (EL) have attracted attention. As examples of such light-emitting elements used in such self-luminous display devices, an organic EL element and an inorganic EL element are known. These light-emitting elements emit light by themselves; thus the visibility of an image on a display device including the organic EL element or the inorganic EL element is higher than that of an image on a display device including a liquid crystal element. Further, the organic EL element and the inorganic EL element have advantages such as high response speed and unnecessity of a backlight.
An organic EL element has a structure in which a layer containing a light-emitting organic compound (also referred to as an EL layer) is sandwiched between a pair of electrodes. On application of a voltage to the pair of electrodes, light is emitted from the EL layer. A display device using such an organic EL element is disclosed in Patent Document 1.